Trichloroacetaldehyde

Chlorinated by-products of ethylene oxychlorination typically include 1,1,2-trichloroethane chloral [75-87-6] (trichloroacetaldehyde) trichloroethylene [7901-6]-, 1,1-dichloroethane cis- and /n j -l,2-dichloroethylenes [156-59-2 and 156-60-5]-, 1,1-dichloroethylene [75-35-4] (vinyhdene chloride) 2-chloroethanol [107-07-3]-, ethyl chloride vinyl chloride mono-, di-, tri-, and tetrachloromethanes (methyl chloride [74-87-3], methylene chloride [75-09-2], chloroform, and carbon tetrachloride [56-23-5])-, and higher boiling compounds. The production of these compounds should be minimized to lower raw material costs, lessen the task of EDC purification, prevent fouling in the pyrolysis reactor, and minimize by-product handling and disposal. Of particular concern is chloral, because it polymerizes in the presence of strong acids. Chloral must be removed to prevent the formation of soflds which can foul and clog operating lines and controls (78). 

Trichloroacetaldehyde (chloral) reacts with glucose in the presence of sulfuric acid to form two monoacetals and four diacetals. The trichloro acetal is cleaved by reduction (H2, Raney Ni, 50% NaOH, EtOH, 15 min). The trichloro acetal can probably be cleaved with Zn/AcOH [cf. ROCH(R )OCH2CCl3 cleaved by Zn/ AcOH, AcONa, 20°, 3 h, 90% yield ]. 

The exceptions are formaldehyde, which is nearly completely hydrated in aqueous solution, and aldehydes and ketones with highly electronegative substituents, such as trichloroacetaldehyde and hexafluoroacetone. The data given in Table 8.1 illustrate that the equilibrium constant for hydration decreases with increasing alkyl substitution. 

Trichloroacetaldehyde (chloral) reacts with glucose in the presence of sulfuric acid to form two mono- and four diacetals. ... 

Tlie Ca substituent effects have been experimentally studied by synthesizing and investigating the A -(l,2,2,2-tetrachloroethyl)pyridinium chloride (43). Tlie synthesis of 43 follows the standard three-component reaction. Tliionyl chloride, trichloroacetaldehyde, and pyridine were reacted at 0°C in MeCN to give this salt in excellent yield (Scheme 31). 

When dissolved in water, trichloroacetaldehyde (chloral, CCJ3CHO) exists primarily as chloral hydrate, CCl CHCOH, better known as "knockout drops." Show the structure of chloral hydrate. 

Surprisingly, acetylation in hot pyridine yields the pyridinium salt 10. The amino group has amidine character and is resistant to diazotization, and condenses only with reactive aldehydes such as formaldehyde and trichloroacetaldehyde.41... 

An overview of the reactions involving trihalomethanes (haloforms) CHXYZ, where X, Y, and Z are halogen atoms, has been given in the context of ozone depletion (Hayman and Derwent 1997). Interest in the formation of trichloroacetaldehyde formed from trichloroethane and tetrachloroethene is heightened by the phytotoxicity of trichloroacetic acid (Frank et al. 1994), and by its occurrence in rainwater that seems to be a major source of this contaminant (Muller et al. 1996). The situation in Japan seems, however, to underscore the possible significance of other sources including chlorinated wastewater (Hashimoto et al. 1998). Whereas there is no doubt about the occurrence of trichloroacetic acid in rainwater (Stidson et al. 2004), its major source is unresolved since questions remain on the rate of hydrolysis of trichloroacetaldehyde (Jordan et al. 1999). 

Newman LM, LP Wackett (1991) Fate of 2,2,2-trichloroacetaldehyde (chloral hydrate) produced during trichloroethylene oxidation by methanotrophs. Appl Environ Microbiol 57 2399-2402. 

It has been shown to metabolize trifluoroethene to glyoxylate, difluoroacetate, and the rearranged product trifluoroacetaldehyde (Fox et al. 1990). The last reaction is analogous to the formation of trichloroacetaldehyde from trichloroethene by the same strain (Oldenhuis et al. 1989). 

Mammalian cytochrome P450 2E1 was introduced into tobacco plants that were exposed to trichloroethene in hydroponic medium for 5 d. Trichloroethene epoxide was produced initially, and was rearranged to trichloroacetaldehyde, which was then reduced to trichloro-ethanol. This was found in samples of leaves, stems, and roots, but was absent in the control plants. Trichloroethanol was subsequently transported to the leaves where it was apparently metabolized (Doty et al. 2000). 

Methanol, ethanol and 3-methylbutanol [1], acetaldehyde, trichloroacetaldehyde [2] and acetone [3] all ignite in contact with gaseous fluorine. Lactic acid, benzoic acid and salicylic acid ignite, while gallic acid becomes incandescent. Ethyl acetate and methyl borate ignite in fluorine [2],... 

Tribromopropane Tributylamine Tributyl borate Tributyl phosphate Tributyl phosphite Trichloroacetaldehyde... 

Blossom, S.J., Pumford, N.R., and Gilbert, K.M., Activation and attenuation of apoptosis of CD4+ T cells following in vivo exposure to two common environmental toxicants, trichloroacetaldehyde hydrate and trichloroacetic acid, J. Autoimmun., 23, 211, 2004. 

Sodium lns(0.0-1 -oximatonaphthalcnc-1,2-dione)fcrratc. 3871 Trichloroacetaldehyde oxime, 0698... 

The same carcinogen can also be formed during the anaerobic metabolism of 1,1- and Zrans-1,2-dichlorethylene [196]. TCE can also be converted in cultures of methanotrophs to 2,2,2-trichloroacetaldehyde [197] ... 

CHLORO-1,1-DIFLUOROETHYLENE TRICHLOROETHYLENE DICHLOROACETYL CHLORIDE TRICHLOROACETALDEHYDE PENTACHLOROETHANE TRIFLUOROETHENE TRIFLUOROACETIC ACID PENTAFLUOROETHANE ACETYLENE... 

Photolytic. Reported photooxidation products include phosgene, chlorine, HCl, and carbon dioxide (McNally and Grob, 1984). Acetyl chloride (Christiansen et al, 1972) and trichloroacetaldehyde (U.S. EPA, 1975) have also been reported as photooxldatlon products. 

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